1. Field of the Invention
The present invention relates to a matrix display device, such as a plasma display panel (PDP), an inorganic or organic electroluminescent (EL) panel, or a liquid crystal panel, capable of displaying an input video signal with high image quality, when the input video signal is a telecine-converted video signal which is converted from a picture like an movie film by means of a conversion system such as a 2-3 pulldown system.
2. Description of the Related Background Art
video signals of a standard television system like the NTSC system often include a video signal based on a movie film. A movie film includes twenty-four frames per second. On the other hand, the video signal of the standard television system includes thirty frames per second and is a video signal using an interlaced scanning system, each of which consists of two fields. Since the numbers of frames per second are different from each other, a 2-3 pulldown system is generally used in order to obtain a video signal of the standard television system from a movie film. In the 2-3 pulldown system, the video signal is generated by telecine-converting respective frames of a movie film.
In the telecine-conversion of the 2-3 pulldown system, a first field and a second field for the first frame of the video signal are formed from a first frame of the movie film, a first field and a second field for a second frame and the first field for a third frame of the video signal are formed from the second frame of the movie film, and a second field for the third frame and a first field for a fourth frame of the video signal are formed from a third frame of the movie film. Likewise, for subsequent frames of the movie film, two fields, three fields, two fields, three fields, . . . of the video signal are formed from the respective frames of the movie film by means of the same conversion scheme.
For every two continuos frames of the movie film, five fields of the video signal of the standard television system are converted. The first frame of the two continuos frames correspond to the beginning two fields of the five fields and the second frame of the two continues frames correspond to the remaining three fields of the five fields.
In displaying the telecine-converted pictures of the video signal of interlaced scanning on a display device like a PDP, the above third frame, for example, of continuous frames of the video signal is formed by combining the pictures of the second and third frames of the movie film. Therefore, there is a problem that each picture displayed in accordance with the video signal is inferior to that of an original movie film in picture quality.
An object of the present invention, therefore, is to provide a display device which is capable of obtaining high display quality for telecine-converted pictures.
A display device according to the present invention comprises a detector for detecting whether or not an input video signal of interlaced scanning is a telecine-converted video signal by unit of field obtained by telecine-converting a film source which has 24 frames per second; a line sequential scan convertor for converting the inputted video signal of interlaced scanning into a video signal of line sequential scanning by field-to-field interpolation processing using fields of the same film frame if the detector determines that the input video signal of interlaced scanning is a telecine-converted video signal; a memory; a memory controller of thinning out the video signal of line sequential scanning converted by the line sequential scan convertor to write it into the memory by unit of field, and repeatedly reading the video signal of line sequential scanning written into the memory by n times from the memory at a rate of n times (n: an integer of 2 or more) as large as 24 Hz; and a driving device for driving a display panel with the video signal of line sequential scanning read from the memory.